CVE-2026-45984: Linux kernel · gfs2: Fix use-after-free in iomap inline data write path
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in faddeb848305e79db89ee0479bb0e33380656321 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in faddeb848305e79db89ee0479bb0e33380656321, d87268326b277af3665237ac76a73dd9fa8e21b4, 1403989d1b502f4a2c0d0b42ccf1c25748442eff +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in iomap inline data write path The inline data buffer head (dibh) is being released prematurely in gfs2_iomap_begin() via release_metapath() while iomap->inline_data still points to dibh->b_data. This causes a use-after-free when iomap_write_end_inline() later attempts to write to the inline data area. The bug sequence: 1. gfs2_iomap_begin() calls gfs2_meta_inode_buffer() to read inode metadata into dibh 2. Sets iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode) 3. Calls release_metapath() which calls brelse(dibh), dropping refcount to 0 4. kswapd reclaims the page (~39ms later in the syzbot report) 5. iomap_write_end_inline() tries to memcpy() to iomap->inline_data 6. KASAN detects use-after-free write to freed memory Fix by storing dibh in iomap->private and incrementing its refcount with get_bh() in gfs2_iomap_begin(). The buffer is then properly released in gfs2_iomap_end() after the inline write completes, ensuring the page stays alive for the entire iomap operation. Note: A C reproducer is not available for this issue. The fix is based on analysis of the KASAN report and code review showing the buffer head is freed before use. [agruenba: Take buffer head reference in gfs2_iomap_begin() to avoid leaks in gfs2_iomap_get() and gfs2_iomap_alloc().]
References
- git.kernel.org/stable/c/1403989d1b502f4a2c0d0b42ccf1c25748442eff (opens in a new tab)
- git.kernel.org/stable/c/1cae1bafdf9caa9b462b19af06b1a06902e4e142 (opens in a new tab)
- git.kernel.org/stable/c/764c3c84b5683e608f43735c803a5f415046686c (opens in a new tab)
- git.kernel.org/stable/c/d87268326b277af3665237ac76a73dd9fa8e21b4 (opens in a new tab)
- git.kernel.org/stable/c/87d4954b5c59735a99ea98cb208d47130f6dce7d (opens in a new tab)
- git.kernel.org/stable/c/6d76febba07c40bcf358f63216d36ea68cf1c215 (opens in a new tab)
- git.kernel.org/stable/c/815ddd27c0c7171a99fe802fdb19098ddef8b19d (opens in a new tab)
- git.kernel.org/stable/c/faddeb848305e79db89ee0479bb0e33380656321 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-45984 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2481922 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45984.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:61692 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:63189 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51603 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36767 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38902 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27789 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59143 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33743 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59146 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35894 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55444 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59142 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59147 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59145 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59148 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59149 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36049 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51604 (opens in a new tab)